CVS EKG Flashcards
what can you inspect from an ECG?
- heart rate
- rhythm
- duration, intervals, segments
- arrhythmias
how is HR calculated?
count divisions in R-R interval = 26
time per each division = 0.04 s
26 x 0.04 = each beat takes 1.04s
in 1 minute of beat = 60/1.04 = 57 bpm
what leads would you find an upright P wave?
leads I, II, III
when looking at rhythm what should I notice
each QRS complex should follow a P wave
each QRS complex should be preceded by a P wave
define cardiac arrhythmia
change in cardiac rhythm from the “normal sinus rhythm”
what are the normal arrhythmias
sinus tachycardia
sinus arrhythmia
what evokes sinus tachycardia?
exercise, fright (increase in sympathetics)
what evokes sinus arrhythmia
change in HR with the respiratory cycle
slight increase in HR in inspiration
slight decrease in HR in expiration
what are the 2 causes of arrhythmias
altered conduction
altered automaticity
where may disturbances of conduction occur
anywhere along the conducting pathway
may be partial or complete
define fibrillation
frequency of generation of AP is so high that there is no coordinated contraction of the myocardium
what is atrial fibrillation
constant electrical activity across the atria in wave
they are not coordinated
not pumping, just wobbling
few of the atrial depolarizations manage to get through to the AV node
common, not a huge problem because the ventricles suck blood in when they relax
becomes a problem in old age
what is ventricular fibrillation
you NEED coordination here - if there isn’t, you don’t get cardiac output (CO) this is an emergency => death if not treated immediately
this is why they have defribillators around!
